diff --git a/rules/salty-dog.yml b/rules/salty-dog.yml
index 0718b56..484e8da 100644
--- a/rules/salty-dog.yml
+++ b/rules/salty-dog.yml
@@ -20,7 +20,6 @@ rules:
         - tags
         # data
         - select
-        - filter
         - check
       properties:
         name:
@@ -33,6 +32,7 @@ rules:
           type: array
           items:
             type: string
+            pattern: "[-:a-z0-9]+"
         select:
           type: string
         filter: